/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: ResultTreeType.java,v 1.2.4.1 2005/09/05 11:30:01 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.compiler.util;

import com.sun.org.apache.bcel.internal.generic.ALOAD;
import com.sun.org.apache.bcel.internal.generic.ASTORE;
import com.sun.org.apache.bcel.internal.generic.CHECKCAST;
import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.GETFIELD;
import com.sun.org.apache.bcel.internal.generic.IFEQ;
import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;
import com.sun.org.apache.bcel.internal.generic.INVOKESPECIAL;
import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;
import com.sun.org.apache.bcel.internal.generic.Instruction;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.LocalVariableGen;
import com.sun.org.apache.bcel.internal.generic.NEW;
import com.sun.org.apache.bcel.internal.generic.PUSH;
import com.sun.org.apache.xalan.internal.xsltc.compiler.Constants;
import com.sun.org.apache.xalan.internal.xsltc.compiler.FlowList;

/**
 * @author Jacek Ambroziak
 * @author Santiago Pericas-Geertsen
 * @author Morten Jorgensen
 */
public final class ResultTreeType extends Type {

  private final String _methodName;

  protected ResultTreeType() {
    _methodName = null;
  }

  public ResultTreeType(String methodName) {
    _methodName = methodName;
  }

  public String toString() {
    return "result-tree";
  }

  public boolean identicalTo(Type other) {
    return (other instanceof ResultTreeType);
  }

  public String toSignature() {
    return DOM_INTF_SIG;
  }

  public com.sun.org.apache.bcel.internal.generic.Type toJCType() {
    return Util.getJCRefType(toSignature());
  }

  public String getMethodName() {
    return _methodName;
  }

  public boolean implementedAsMethod() {
    return _methodName != null;
  }

  /**
   * Translates a result tree to object of internal type <code>type</code>.
   * The translation to int is undefined since result trees
   * are always converted to reals in arithmetic expressions.
   *
   * @param classGen A BCEL class generator
   * @param methodGen A BCEL method generator
   * @param type An instance of the type to translate the result tree to
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      Type type) {
    if (type == Type.String) {
      translateTo(classGen, methodGen, (StringType) type);
    } else if (type == Type.Boolean) {
      translateTo(classGen, methodGen, (BooleanType) type);
    } else if (type == Type.Real) {
      translateTo(classGen, methodGen, (RealType) type);
    } else if (type == Type.NodeSet) {
      translateTo(classGen, methodGen, (NodeSetType) type);
    } else if (type == Type.Reference) {
      translateTo(classGen, methodGen, (ReferenceType) type);
    } else if (type == Type.Object) {
      translateTo(classGen, methodGen, (ObjectType) type);
    } else {
      ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
          toString(), type.toString());
      classGen.getParser().reportError(Constants.FATAL, err);
    }
  }

  /**
   * Expects an result tree on the stack and pushes a boolean.
   * Translates a result tree to a boolean by first converting it to string.
   *
   * @param classGen A BCEL class generator
   * @param methodGen A BCEL method generator
   * @param type An instance of BooleanType (any)
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      BooleanType type) {
    // A result tree is always 'true' when converted to a boolean value,
    // since the tree always has at least one node (the root).
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();
    il.append(POP);      // don't need the DOM reference
    il.append(ICONST_1); // push 'true' on the stack
  }

  /**
   * Expects an result tree on the stack and pushes a string.
   *
   * @param classGen A BCEL class generator
   * @param methodGen A BCEL method generator
   * @param type An instance of StringType (any)
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      StringType type) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();

    if (_methodName == null) {
      int index = cpg.addInterfaceMethodref(DOM_INTF,
          "getStringValue",
          "()" + STRING_SIG);
      il.append(new INVOKEINTERFACE(index, 1));
    } else {
      final String className = classGen.getClassName();
      final int current = methodGen.getLocalIndex("current");

      // Push required parameters
      il.append(classGen.loadTranslet());
      if (classGen.isExternal()) {
        il.append(new CHECKCAST(cpg.addClass(className)));
      }
      il.append(DUP);
      il.append(new GETFIELD(cpg.addFieldref(className, "_dom",
          DOM_INTF_SIG)));

      // Create a new instance of a StringValueHandler
      int index = cpg.addMethodref(STRING_VALUE_HANDLER, "<init>", "()V");
      il.append(new NEW(cpg.addClass(STRING_VALUE_HANDLER)));
      il.append(DUP);
      il.append(DUP);
      il.append(new INVOKESPECIAL(index));

      // Store new Handler into a local variable
      final LocalVariableGen handler =
          methodGen.addLocalVariable("rt_to_string_handler",
              Util.getJCRefType(STRING_VALUE_HANDLER_SIG),
              null, null);
      handler.setStart(il.append(new ASTORE(handler.getIndex())));

      // Call the method that implements this result tree
      index = cpg.addMethodref(className, _methodName,
          "(" + DOM_INTF_SIG + TRANSLET_OUTPUT_SIG + ")V");
      il.append(new INVOKEVIRTUAL(index));

      // Restore new handler and call getValue()
      handler.setEnd(il.append(new ALOAD(handler.getIndex())));
      index = cpg.addMethodref(STRING_VALUE_HANDLER,
          "getValue",
          "()" + STRING_SIG);
      il.append(new INVOKEVIRTUAL(index));
    }
  }

  /**
   * Expects an result tree on the stack and pushes a real.
   * Translates a result tree into a real by first converting it to string.
   *
   * @param classGen A BCEL class generator
   * @param methodGen A BCEL method generator
   * @param type An instance of RealType (any)
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      RealType type) {
    translateTo(classGen, methodGen, Type.String);
    Type.String.translateTo(classGen, methodGen, Type.Real);
  }

  /**
   * Expects a result tree on the stack and pushes a boxed result tree.
   * Result trees are already boxed so the translation is just a NOP.
   *
   * @param classGen A BCEL class generator
   * @param methodGen A BCEL method generator
   * @param type An instance of ReferenceType (any)
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      ReferenceType type) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();

    if (_methodName == null) {
      il.append(NOP);
    } else {
      LocalVariableGen domBuilder, newDom;
      final String className = classGen.getClassName();
      final int current = methodGen.getLocalIndex("current");

      // Push required parameters
      il.append(classGen.loadTranslet());
      if (classGen.isExternal()) {
        il.append(new CHECKCAST(cpg.addClass(className)));
      }
      il.append(methodGen.loadDOM());

      // Create new instance of DOM class (with RTF_INITIAL_SIZE nodes)
      il.append(methodGen.loadDOM());
      int index = cpg.addInterfaceMethodref(DOM_INTF,
          "getResultTreeFrag",
          "(IZ)" + DOM_INTF_SIG);
      il.append(new PUSH(cpg, RTF_INITIAL_SIZE));
      il.append(new PUSH(cpg, false));
      il.append(new INVOKEINTERFACE(index, 3));
      il.append(DUP);

      // Store new DOM into a local variable
      newDom = methodGen.addLocalVariable("rt_to_reference_dom",
          Util.getJCRefType(DOM_INTF_SIG),
          null, null);
      il.append(new CHECKCAST(cpg.addClass(DOM_INTF_SIG)));
      newDom.setStart(il.append(new ASTORE(newDom.getIndex())));

      // Overwrite old handler with DOM handler
      index = cpg.addInterfaceMethodref(DOM_INTF,
          "getOutputDomBuilder",
          "()" + TRANSLET_OUTPUT_SIG);

      il.append(new INVOKEINTERFACE(index, 1));
      //index = cpg.addMethodref(DOM_IMPL,
      //                   "getOutputDomBuilder",
      //                   "()" + TRANSLET_OUTPUT_SIG);
      //il.append(new INVOKEVIRTUAL(index));
      il.append(DUP);
      il.append(DUP);

      // Store DOM handler in a local in order to call endDocument()
      domBuilder =
          methodGen.addLocalVariable("rt_to_reference_handler",
              Util.getJCRefType(TRANSLET_OUTPUT_SIG),
              null, null);
      domBuilder.setStart(il.append(new ASTORE(domBuilder.getIndex())));

      // Call startDocument on the new handler
      index = cpg.addInterfaceMethodref(TRANSLET_OUTPUT_INTERFACE,
          "startDocument", "()V");
      il.append(new INVOKEINTERFACE(index, 1));

      // Call the method that implements this result tree
      index = cpg.addMethodref(className,
          _methodName,
          "("
              + DOM_INTF_SIG
              + TRANSLET_OUTPUT_SIG
              + ")V");
      il.append(new INVOKEVIRTUAL(index));

      // Call endDocument on the DOM handler
      domBuilder.setEnd(il.append(new ALOAD(domBuilder.getIndex())));
      index = cpg.addInterfaceMethodref(TRANSLET_OUTPUT_INTERFACE,
          "endDocument", "()V");
      il.append(new INVOKEINTERFACE(index, 1));

      // Push the new DOM on the stack
      newDom.setEnd(il.append(new ALOAD(newDom.getIndex())));
    }
  }

  /**
   * Expects a result tree on the stack and pushes a node-set (iterator).
   * Note that the produced iterator is an iterator for the DOM that
   * contains the result tree, and not the DOM that is currently in use.
   * This conversion here will therefore not directly work with elements
   * such as <xsl:apply-templates> and <xsl:for-each> without the DOM
   * parameter/variable being updates as well.
   *
   * @param classGen A BCEL class generator
   * @param methodGen A BCEL method generator
   * @param type An instance of NodeSetType (any)
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      NodeSetType type) {
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();

    // Put an extra copy of the result tree (DOM) on the stack
    il.append(DUP);

    // DOM adapters containing a result tree are not initialised with
    // translet-type to DOM-type mapping. This must be done now for
    // XPath expressions and patterns to work for the iterator we create.
    il.append(classGen.loadTranslet()); // get names array
    il.append(new GETFIELD(cpg.addFieldref(TRANSLET_CLASS,
        NAMES_INDEX,
        NAMES_INDEX_SIG)));
    il.append(classGen.loadTranslet()); // get uris array
    il.append(new GETFIELD(cpg.addFieldref(TRANSLET_CLASS,
        URIS_INDEX,
        URIS_INDEX_SIG)));
    il.append(classGen.loadTranslet()); // get types array
    il.append(new GETFIELD(cpg.addFieldref(TRANSLET_CLASS,
        TYPES_INDEX,
        TYPES_INDEX_SIG)));
    il.append(classGen.loadTranslet()); // get namespaces array
    il.append(new GETFIELD(cpg.addFieldref(TRANSLET_CLASS,
        NAMESPACE_INDEX,
        NAMESPACE_INDEX_SIG)));
    // Pass the type mappings to the DOM adapter
    final int mapping = cpg.addInterfaceMethodref(DOM_INTF,
        "setupMapping",
        "([" + STRING_SIG +
            "[" + STRING_SIG +
            "[I" +
            "[" + STRING_SIG + ")V");
    il.append(new INVOKEINTERFACE(mapping, 5));
    il.append(DUP);

    // Create an iterator for the root node of the DOM adapter
    final int iter = cpg.addInterfaceMethodref(DOM_INTF,
        "getIterator",
        "()" + NODE_ITERATOR_SIG);
    il.append(new INVOKEINTERFACE(iter, 1));
  }

  /**
   * Subsume result tree into ObjectType.
   *
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      ObjectType type) {
    methodGen.getInstructionList().append(NOP);
  }

  /**
   * Translates a result tree into a non-synthesized boolean.
   * It does not push a 0 or a 1 but instead returns branchhandle list
   * to be appended to the false list.
   *
   * @param classGen A BCEL class generator
   * @param methodGen A BCEL method generator
   * @param type An instance of BooleanType (any)
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateToDesynthesized
   */
  public FlowList translateToDesynthesized(ClassGenerator classGen,
      MethodGenerator methodGen,
      BooleanType type) {
    final InstructionList il = methodGen.getInstructionList();
    translateTo(classGen, methodGen, Type.Boolean);
    return new FlowList(il.append(new IFEQ(null)));
  }

  /**
   * Translates a result tree to a Java type denoted by <code>clazz</code>.
   * Expects a result tree on the stack and pushes an object
   * of the appropriate type after coercion. Result trees are translated
   * to W3C Node or W3C NodeList and the translation is done
   * via node-set type.
   *
   * @param classGen A BCEL class generator
   * @param methodGen A BCEL method generator
   * @param clazz An reference to the Class to translate to
   * @see com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type#translateTo
   */
  public void translateTo(ClassGenerator classGen, MethodGenerator methodGen,
      Class clazz) {
    final String className = clazz.getName();
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();

    if (className.equals("org.w3c.dom.Node")) {
      translateTo(classGen, methodGen, Type.NodeSet);
      int index = cpg.addInterfaceMethodref(DOM_INTF,
          MAKE_NODE,
          MAKE_NODE_SIG2);
      il.append(new INVOKEINTERFACE(index, 2));
    } else if (className.equals("org.w3c.dom.NodeList")) {
      translateTo(classGen, methodGen, Type.NodeSet);
      int index = cpg.addInterfaceMethodref(DOM_INTF,
          MAKE_NODE_LIST,
          MAKE_NODE_LIST_SIG2);
      il.append(new INVOKEINTERFACE(index, 2));
    } else if (className.equals("java.lang.Object")) {
      il.append(NOP);
    } else if (className.equals("java.lang.String")) {
      translateTo(classGen, methodGen, Type.String);
    } else {
      ErrorMsg err = new ErrorMsg(ErrorMsg.DATA_CONVERSION_ERR,
          toString(), className);
      classGen.getParser().reportError(Constants.FATAL, err);
    }
  }

  /**
   * Translates an object of this type to its boxed representation.
   */
  public void translateBox(ClassGenerator classGen,
      MethodGenerator methodGen) {
    translateTo(classGen, methodGen, Type.Reference);
  }

  /**
   * Translates an object of this type to its unboxed representation.
   */
  public void translateUnBox(ClassGenerator classGen,
      MethodGenerator methodGen) {
    methodGen.getInstructionList().append(NOP);
  }

  /**
   * Returns the class name of an internal type's external representation.
   */
  public String getClassName() {
    return (DOM_INTF);
  }

  public Instruction LOAD(int slot) {
    return new ALOAD(slot);
  }

  public Instruction STORE(int slot) {
    return new ASTORE(slot);
  }
}
